My bloodwork showed severe Vitamin D deficiency (14), so I'm taking supplements (10,000 IU per day). Since last year, I've been experiencing constipation due to lack of moisture in the rectum. Bowel movements have been really painful.
A few months ago, I exprienced dark-colored stool indicating possible bleeding from the upper digestive tract. I also experienced pencil-like, thin stool for a while. Both symptoms have gone away and my stoll is normal now.
But constipation has been chronic, which has led me to consider taking magnesium supplements, since Milk of Magnesia is the only medicine that's been working for me (Neither fiber (Metamucil), lots of water, stool softeners, really worked for me). I may also have hemorrhoids at this point.
My internist recommends a colonoscopy to get to the bottom of this. What do you think is my chances of having colorectal cancer? I do have a small polyp on my gall bladder which is benign. Perhaps I should have listened to my doctor earlier (he recommended colonoscopy 6 months ago). But I'm 45 (50 is the age when a colonoscopy is recommended) and I thougth the procedure might be a too extreme at this stage.